Roll Groove Specifications
- Share
Roll Groove Specifications
Groove specifications for carbon steel pipes and all pipe materials, organized by Welping & Gruvmaster. Dimensions are in millimeters (mm).
Precision Grooving Standards for Reliable Piping Systems
Roll grooving is the preferred method for preparing pipe ends in fire protection, HVAC, and industrial piping systems. A precisely formed groove ensures secure, leak-free connections with grooved couplings, reducing installation time and labor on site.
This reference covers two complete systems: the Original Groove System (OGS) for carbon steel pipe and all materials from 1" to 42", and the Advanced Groove System (AGS) for carbon steel and stainless steel pipe (Schedule 10S) from 14" to 78".
- OGS covers 1"–42" — 42 standard sizes
- AGS covers 14"–78" — 37 standard sizes
- All dimensions verified in millimeters
- Version 2.0 — issued November 2025
OGS Roll Groove Specifications
The Original Groove System (OGS) is designed for carbon steel pipe and all materials, covering pipe sizes from 1" to 42". All dimensions below are in millimeters.
OGS Groove Dimensional Diagram
Key dimensions for the Original Groove System: gasket seat “A”, groove width “B”, groove diameter “C”, and groove depth “D”. All values are shown in millimeters and follow the Welping & Gruvmaster standard (Ver. 2.0).
| Pipe Size | Pipe Outside Diameter | Actual Pipe Outside Diameter (mm) | Gasket Seat “A” (mm) | Groove Width “B” (mm) | Groove Diameter “C” (mm) | Groove Depth “D” (ref) | Min. Allow. Wall Thick “T” | Max. Allow. Flare Dia. “F” | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Basic | Max. | Min. | Basic | Max. | Min. | Max. | Min. | |||||
| 1" | 33.7mm | 34.11 | 33.02 | 15.88 | 16.64 | 15.12 | 7.14 | 7.9 | 6.38 | 30.23 | 29.85 | 1.6 | 1.65 | 34.5 |
| 1-1/4" | 42.4mm | 42.9 | 41.8 | 15.88 | 16.64 | 15.12 | 7.14 | 7.9 | 6.38 | 38.99 | 38.61 | 1.6 | 1.65 | 45 |
| 1-1/2" | 48.3mm | 48.78 | 47.78 | 15.88 | 16.64 | 15.12 | 7.14 | 7.9 | 6.38 | 45.09 | 44.71 | 1.6 | 1.65 | 51.1 |
| 2" | 57.0mm | 57.61 | 56.39 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 53.85 | 53.47 | 1.60 | 1.65 | 59.7 |
| 2" | 60.3mm | 60.91 | 59.69 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 57.15 | 56.77 | 1.60 | 1.65 | 63 0 |
| 2-1/2" | 73.0mm | 73.74 | 72.26 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 69.09 | 68.63 | 1.98 | 2.11 | 75.7 |
| 2-1/2" | 76.1mm | 76.86 | 75.34 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 72.26 | 71.8 | 1.98 | 2.11 | 78.7 |
| 3" | 88.9mm | 89.79 | 88.11 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 84.94 | 84.48 | 1.98 | 2.11 | 91.4 |
| 3-1/2" | 101.6mm | 101.62 | 100.81 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 97.38 | 96.87 | 2.11 | 2.11 | 104.1 |
| 4" | 108.0mm | 109.09 | 107.21 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 103.73 | 103.22 | 2.11 | 2.11 | 110.5 |
| 4" | 114.3mm | 115.44 | 113.51 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 110.08 | 109.57 | 2.11 | 2.11 | 116.8 |
| 5" | 127.0mm | 128.27 | 126.21 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 122.78 | 122.27 | 2.11 | 2.41 | 129.5 |
| 5" | 133.0mm | 134.35 | 132.21 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 129.13 | 128.62 | 2.11 | 2.77 | 135.9 |
| 5" | 139.7mm | 141.12 | 138.91 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 135.48 | 134.97 | 2.11 | 2.77 | 142.2 |
| 5" | 141.3mm | 142.72 | 140.51 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 137.03 | 136.47 | 2.13 | 2.77 | 143.8 |
| 6" | 152.4mm | 153.82 | 151.61 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 148.08 | 147.52 | 2.16 | 2.77 | 154.9 |
| 6" | 159.0mm | 160.6 | 158.21 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 154.68 | 154.12 | 2.16 | 2.77 | 161.3 |
| 6" | 165.1mm | 166.7 | 164.31 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 160.9 | 160.34 | 2.16 | 2.77 | 167.6 |
| 6" | 168.3mm | 169.9 | 167.51 | 15.88 | 16.64 | 15.12 | 8.74 | 9.5 | 7.98 | 163.96 | 163.4 | 2.16 | 2.77 | 170.9 |
| 8" | 203.2mm | 204.8 | 202.41 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 198.53 | 197.89 | 2.34 | 2.77 | 207.5 |
| 8" | 216.3mm | 217.9 | 215.51 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 211.61 | 210.97 | 2.34 | 2.77 | 220.7 |
| 8" | 219.1mm | 220.7 | 218.31 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 214.4 | 213.76 | 2.34 | 2.77 | 223.5 |
| 10" | 254.0mm | 255.6 | 253.21 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 249.23 | 248.54 | 2.39 | 3.4 | 258.3 |
| 10" | 267.4mm | 269.0 | 266.61 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 262.6 | 261.91 | 2.39 | 3.4 | 271.8 |
| 10" | 273.0mm | 274.6 | 272.21 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 268.28 | 267.59 | 2.39 | 3.4 | 277.4 |
| 12" | 304.8mm | 306.4 | 304.01 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 299.24 | 298.48 | 2.77 | 3.96 | 309.1 |
| 12" | 318.5mm | 320.1 | 317.71 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 312.90 | 312.14 | 2.77 | 3.96 | 322.8 |
| 12" | 323.9mm | 325.5 | 323.11 | 19.05 | 19.81 | 18.29 | 11.91 | 12.67 | 11.15 | 318.29 | 317.53 | 2.77 | 3.96 | 328.2 |
| 14" | 355.6mm | 357.2 | 354.81 | 23.83 | 24.59 | 23.07 | 11.91 | 12.67 | 11.15 | 350.04 | 349.28 | 2.77 | 3.96 | 359.7 |
| 14" | 377.0mm | 378.6 | 376.21 | 23.83 | 24.59 | 23.07 | 11.91 | 12.67 | 11.15 | 371.44 | 370.68 | 2.77 | 4.19 | 381.1 |
| 15" | 381.0mm | 382.6 | 379.4 | 23.83 | 24.59 | 23.07 | 11.91 | 12.67 | 11.15 | 375.44 | 374.68 | 2.77 | 4.19 | 385.1 |
| 16" | 406.4mm | 408.0 | 405.61 | 23.83 | 24.59 | 23.07 | 11.91 | 12.67 | 11.15 | 400.84 | 400.08 | 2.77 | 4.19 | 410.5 |
| 18" | 457.2mm | 455.6 | 453.21 | 25.4 | 26.16 | 24.64 | 11.91 | 12.67 | 11.15 | 451.64 | 450.88 | 2.77 | 4.19 | 461.3 |
| 20" | 508mm | 506.4 | 504.01 | 25.4 | 26.16 | 24.64 | 11.91 | 12.67 | 11.15 | 502.44 | 501.68 | 2.77 | 4.78 | 512.1 |
| 22" | 559mm | 557.4 | 555.01 | 25.4 | 26.16 | 24.64 | 12.7 | 13.46 | 11.94 | 550.06 | 549.3 | 4.37 | 4.78 | 563.9 |
| 24" | 610mm | 611.6 | 609.21 | 25.4 | 26.16 | 24.64 | 12.7 | 13.46 | 11.94 | 600.86 | 600.1 | 4.37 | 5.54 | 614.7 |
| 26" | 660.4mm | 662.76 | 659.61 | 44.45 | 45.21 | 43.69 | 15.88 | 16.64 | 15.12 | 647.7 | 646.1 | 6.35 | 6.35 | 665.5 |
| 28" | 711.0mm | 713.36 | 710.21 | 44.45 | 45.21 | 43.69 | 15.88 | 16.64 | 15.12 | 698.5 | 696.9 | 6.35 | 6.35 | 716.3 |
| 30" | 762.0mm | 764.36 | 761.21 | 44.45 | 45.21 | 43.69 | 15.88 | 16.64 | 15.12 | 749.3 | 747.7 | 6.35 | 6.35 | 767.1 |
| 32" | 813.0mm | 815.36 | 812.21 | 44.45 | 45.21 | 43.69 | 15.88 | 16.64 | 15.12 | 800.1 | 798.5 | 6.35 | 6.35 | 817.9 |
| 36" | 914.0mm | 916.36 | 913.21 | 44.45 | 45.21 | 43.69 | 15.88 | 16.64 | 15.12 | 901.7 | 900.1 | 6.35 | 6.35 | 919.5 |
| 42" | 1067.0mm | 1069.36 | 1066.21 | 50.8 | 51.56 | 50.04 | 15.88 | 16.64 | 15.12 | 1054.1 | 1052.5 | 6.35 | 6.35 | 1071.8 |
AGS Roll Groove Specifications
The Advanced Groove System (AGS) is designed for carbon steel pipe and stainless steel pipe (Schedule 10S), covering pipe sizes from 14" to 78". All dimensions below are in millimeters.
AGS Groove Dimensional Diagram
Key dimensions for the Advanced Groove System: gasket seat “A”, groove width “B”, groove diameter “C”, and nominal wall thickness for grooving “T”. All values are shown in millimeters and follow the Welping & Gruvmaster standard (Ver. 2.0).
| Pipe Size | Pipe Outside Diameter | Actual Pipe Outside Diameter (mm) | Gasket Seat “A” (mm) | Groove Width “B” | Groove Diameter “C” (mm) | Nominal Wall Thickness for Grooving “T” | Max. Allow. Flare Dia. “F” | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Basic | Max. | Min. | Max. | Min. | Carbon Steel | S.S Steel Sch.10S | ||||
| 14" | 355.6mm | 358.0 | 354.8 | 38.1 | 38.89 | 36.5 | 11.6 | 342.9 | 341.8 | 5.6–19.1 | 4.8 | 361.4 |
| 14" | 377.0mm | 379.4 | 376.2 | 38.1 | 38.89 | 36.5 | 11.6 | 364.3 | 363.2 | 5.5–19.1 | – | 382.8 |
| 16" | 406.4mm | 408.8 | 405.6 | 38.1 | 38.89 | 36.5 | 11.6 | 393.7 | 392.6 | 6.4–19.1 | 4.8 | 412.2 |
| 16" | 426.0mm | 428.4 | 425.2 | 38.1 | 38.89 | 36.5 | 11.6 | 413.3 | 412.2 | 6.5–19.1 | – | 431.8 |
| 18" | 457.2mm | 459.6 | 456.4 | 38.1 | 38.89 | 36.5 | 11.6 | 444.5 | 443.4 | 6.4–19.1 | 4.8 | 463.0 |
| 18" | 480.0mm | 482.4 | 479.2 | 38.1 | 38.89 | 36.5 | 11.6 | 467.3 | 466.2 | 6.5–19.1 | – | 485.9 |
| 20" | 508.0mm | 510.4 | 507.2 | 38.1 | 38.89 | 36.5 | 11.6 | 495.3 | 494.2 | 6.4–19.1 | 5.5 | 513.8 |
| 20" | 530.0mm | 532.4 | 529.2 | 38.1 | 38.89 | 36.5 | 11.6 | 517.3 | 516.2 | 6.5–19.1 | – | 535.7 |
| 22" | 558.8mm | 561.2 | 558.0 | 38.1 | 38.89 | 36.5 | 11.6 | 546.1 | 545.0 | 6.4–19.1 | 5.5 | 564.6 |
| 24" | 609.6mm | 612.0 | 608.8 | 38.1 | 38.89 | 36.5 | 11.6 | 596.9 | 595.8 | 6.4–19.1 | 5.5 | 615.4 |
| 24" | 630.0mm | 632.4 | 629.2 | 38.1 | 38.89 | 36.5 | 11.6 | 617.3 | 616.2 | 6.5–19.1 | – | 635.8 |
| 26" | 660.4mm | 662.0 | 658.8 | 44.5 | 45.29 | 42.9 | 13.6 | 645.9 | 644.4 | 8.0–19.1 | – | 668.0 |
| 28" | 711.2mm | 712.8 | 709.6 | 44.5 | 45.29 | 42.9 | 13.6 | 696.7 | 695.2 | 8.0–19.1 | – | 718.8 |
| 28" | 720.0mm | 721.6 | 718.4 | 44.5 | 45.29 | 42.9 | 13.6 | 705.5 | 704.0 | 8.0–19.1 | – | 727.6 |
| 30" | 762.0mm | 763.6 | 760.4 | 44.5 | 45.29 | 42.9 | 13.6 | 747.5 | 746.0 | 8.0–19.1 | – | 769.6 |
| 32" | 812.8mm | 814.4 | 811.2 | 44.5 | 45.29 | 42.9 | 13.6 | 798.3 | 796.8 | 8.0–19.1 | – | 820.4 |
| 32" | 820.0mm | 821.6 | 818.4 | 44.5 | 45.29 | 42.9 | 13.6 | 805.5 | 804.0 | 8.0–19.1 | – | 827.6 |
| 34" | 863.6mm | 865.2 | 862.0 | 44.5 | 45.29 | 42.9 | 13.6 | 849.1 | 847.6 | 8.0–19.1 | – | 871.2 |
| 36" | 914.4mm | 916.0 | 912.8 | 44.5 | 45.29 | 42.9 | 13.6 | 899.9 | 898.4 | 8.0–19.1 | – | 922.0 |
| 36" | 920.0mm | 921.6 | 918.4 | 44.5 | 45.29 | 42.9 | 13.6 | 905.5 | 904.0 | 8.0–19.1 | – | 927.6 |
| 38" | 965.0mm | 966.6 | 963.4 | 44.5 | 45.29 | 42.9 | 13.6 | 950.7 | 949.2 | 8.0–19.1 | – | 972.8 |
| 40" | 1016.0mm | 1017.6 | 1014.4 | 50.8 | 51.59 | 49.2 | 14.3 | 1000.1 | 998.6 | 8.0–19.1 | – | 1023.6 |
| 42" | 1066.8mm | 1068.4 | 1065.2 | 50.8 | 51.59 | 49.2 | 14.3 | 1050.9 | 1049.4 | 8.0–19.1 | – | 1074.4 |
| 44" | 1117.6mm | 1119.2 | 1116.0 | 50.8 | 51.59 | 49.2 | 14.3 | 1101.7 | 1100.2 | 8.0–19.1 | – | 1125.2 |
| 46" | 1168.4mm | 1170.0 | 1166.8 | 50.8 | 51.59 | 49.2 | 14.3 | 1152.5 | 1151.0 | 8.0–19.1 | – | 1176.0 |
| 48" | 1219.2mm | 1220.8 | 1217.6 | 50.8 | 51.59 | 49.2 | 14.3 | 1203.3 | 1201.8 | 8.0–19.1 | – | 1226.8 |
| 50" | 1270.0mm | 1271.6 | 1268.4 | 50.8 | 51.59 | 49.2 | 14.3 | 1254.1 | 1252.6 | 8.0–19.1 | – | 1277.6 |
| 54" | 1371.6mm | 1373.2 | 1370.0 | 63.5 | 64.29 | 61.9 | 14.3 | 1357.1 | 1355.6 | 9.5–19.1 | – | 1379.2 |
| 56" | 1422.4mm | 1424.0 | 1420.8 | 63.5 | 64.29 | 61.9 | 14.3 | 1407.9 | 1406.4 | 9.5–19.1 | – | 1430.0 |
| 58" | 1473.2mm | 1474.8 | 1471.6 | 63.5 | 64.29 | 61.9 | 14.3 | 1458.7 | 1457.2 | 9.5–19.1 | – | 1480.8 |
| 60" | 1524.0mm | 1525.6 | 1522.4 | 63.5 | 64.29 | 61.9 | 14.3 | 1509.5 | 1508.0 | 9.5–19.1 | – | 1531.6 |
| 62" | 1574.8mm | 1576.4 | 1573.2 | 63.5 | 64.29 | 61.9 | 14.3 | 1560.3 | 1558.8 | 9.5–19.1 | – | 1582.4 |
| 64" | 1625.6mm | 1627.2 | 1624.0 | 63.5 | 64.29 | 61.9 | 14.3 | 1611.1 | 1609.6 | 12.7–19.1 | – | 1633.2 |
| 66" | 1676.4mm | 1678.0 | 1674.8 | 63.5 | 64.29 | 61.9 | 14.3 | 1661.9 | 1660.4 | 12.7–19.1 | – | 1684.0 |
| 68" | 1727.2mm | 1728.8 | 1725.6 | 63.5 | 64.29 | 61.9 | 14.3 | 1712.7 | 1711.2 | 12.7–19.1 | – | 1734.8 |
| 72" | 1828.8mm | 1830.4 | 1827.2 | 63.5 | 64.29 | 61.9 | 14.3 | 1814.3 | 1812.8 | 12.7–19.1 | – | 1836.4 |
| 78" | 1981.2mm | 1982.8 | 1979.6 | 63.5 | 64.29 | 61.9 | 14.3 | 1966.7 | 1965.2 | 12.7–19.1 | – | 1990.3 |
Where These Groove Standards Are Applied
Both OGS and AGS specifications are engineered for grooved piping systems used across demanding industries:
- Fire Protection — sprinkler and standpipe systems built to NFPA standards
- HVAC & Refrigeration — chilled water, condenser, and hot water piping
- Industrial Piping — mining, chemical, and process plants with heavy-wall pipe
- Water & Wastewater — municipal and commercial distribution lines
The correct groove depth and diameter are essential for coupling performance. Always verify the actual pipe outside diameter before grooving, and confirm that the pipe wall thickness meets the minimum allowable value listed for the selected groove system.
1. Measure Pipe OD
Measure the actual outside diameter of the pipe and select the matching size row in the table.
2. Verify Wall Thickness
Confirm the pipe wall thickness meets the minimum allowable value “T” for the groove system.
3. Set Groove Rollers
Set the grooving machine rollers according to groove width “B” and diameter “C” values.
4. Verify Groove
Check the finished groove with a go/no-go gauge to confirm depth and diameter tolerance.
Check Pipe OD & Schedule Wall Thickness
Before applying the OGS or AGS groove dimensions on this page, confirm the pipe's nominal size, actual outside diameter, and listed Schedule wall thickness in the companion chart.
Need Assistance with Groove Specifications?
Our engineering team can help you confirm the right groove dimensions for your pipe material, wall thickness, and coupling system. We also provide downloadable groove specification documents for both OGS and AGS systems.